// ASM: a very small and fast Java bytecode manipulation framework
// Copyright (c) 2000-2011 INRIA, France Telecom
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
// 3. Neither the name of the copyright holders nor the names of its
//    contributors may be used to endorse or promote products derived from
//    this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.
package org.objectweb.asm.tree;

import java.util.ArrayList;
import java.util.List;
import org.objectweb.asm.AnnotationVisitor;
import org.objectweb.asm.Opcodes;

/**
 * A node that represents an annotation.
 *
 * @author Eric Bruneton
 */
public class AnnotationNode extends AnnotationVisitor {

	/** The class descriptor of the annotation class. */
	public String desc;

	/**
	 * The name value pairs of this annotation. Each name value pair is stored as two consecutive elements in the list. The name is a {@link String}, and the value may be a {@link Byte}, {@link Boolean}, {@link Character}, {@link Short}, {@link Integer}, {@link Long}, {@link Float}, {@link Double}, {@link String} or {@link org.objectweb.asm.Type}, or a two elements String array (for enumeration values), an {@link AnnotationNode}, or a {@link List} of values of one of the preceding types. The list may be {@literal null} if there is no name value pair.
	 */
	public List<Object> values;

	/**
	 * Constructs a new {@link AnnotationNode}. <i>Subclasses must not use this constructor</i>. Instead, they must use the {@link #AnnotationNode(int, String)} version.
	 *
	 * @param descriptor
	 *          the class descriptor of the annotation class.
	 * @throws IllegalStateException
	 *           If a subclass calls this constructor.
	 */
	public AnnotationNode(final String descriptor) {
		this(Opcodes.ASM7, descriptor);
		if (getClass() != AnnotationNode.class) {
			throw new IllegalStateException();
		}
	}

	/**
	 * Constructs a new {@link AnnotationNode}.
	 *
	 * @param api
	 *          the ASM API version implemented by this visitor. Must be one of {@link Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6} or {@link Opcodes#ASM7}.
	 * @param descriptor
	 *          the class descriptor of the annotation class.
	 */
	public AnnotationNode(final int api, final String descriptor) {
		super(api);
		this.desc = descriptor;
	}

	/**
	 * Constructs a new {@link AnnotationNode} to visit an array value.
	 *
	 * @param values
	 *          where the visited values must be stored.
	 */
	AnnotationNode(final List<Object> values) {
		super(Opcodes.ASM7);
		this.values = values;
	}

	// ------------------------------------------------------------------------
	// Implementation of the AnnotationVisitor abstract class
	// ------------------------------------------------------------------------

	@Override
	public void visit(final String name, final Object value) {
		if (values == null) {
			values = new ArrayList<>(this.desc != null ? 2 : 1);
		}
		if (this.desc != null) {
			values.add(name);
		}
		if (value instanceof byte[]) {
			values.add(Util.asArrayList((byte[]) value));
		} else if (value instanceof boolean[]) {
			values.add(Util.asArrayList((boolean[]) value));
		} else if (value instanceof short[]) {
			values.add(Util.asArrayList((short[]) value));
		} else if (value instanceof char[]) {
			values.add(Util.asArrayList((char[]) value));
		} else if (value instanceof int[]) {
			values.add(Util.asArrayList((int[]) value));
		} else if (value instanceof long[]) {
			values.add(Util.asArrayList((long[]) value));
		} else if (value instanceof float[]) {
			values.add(Util.asArrayList((float[]) value));
		} else if (value instanceof double[]) {
			values.add(Util.asArrayList((double[]) value));
		} else {
			values.add(value);
		}
	}

	@Override
	public void visitEnum(final String name, final String descriptor, final String value) {
		if (values == null) {
			values = new ArrayList<>(this.desc != null ? 2 : 1);
		}
		if (this.desc != null) {
			values.add(name);
		}
		values.add(new String[] { descriptor, value });
	}

	@Override
	public AnnotationVisitor visitAnnotation(final String name, final String descriptor) {
		if (values == null) {
			values = new ArrayList<>(this.desc != null ? 2 : 1);
		}
		if (this.desc != null) {
			values.add(name);
		}
		AnnotationNode annotation = new AnnotationNode(descriptor);
		values.add(annotation);
		return annotation;
	}

	@Override
	public AnnotationVisitor visitArray(final String name) {
		if (values == null) {
			values = new ArrayList<>(this.desc != null ? 2 : 1);
		}
		if (this.desc != null) {
			values.add(name);
		}
		List<Object> array = new ArrayList<>();
		values.add(array);
		return new AnnotationNode(array);
	}

	@Override
	public void visitEnd() {
		// Nothing to do.
	}

	// ------------------------------------------------------------------------
	// Accept methods
	// ------------------------------------------------------------------------

	/**
	 * Checks that this annotation node is compatible with the given ASM API version. This method checks that this node, and all its children recursively, do not contain elements that were introduced in more recent versions of the ASM API than the given version.
	 *
	 * @param api
	 *          an ASM API version. Must be one of {@link Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6} or {@link Opcodes#ASM7}.
	 */
	public void check(final int api) {
		// nothing to do
	}

	/**
	 * Makes the given visitor visit this annotation.
	 *
	 * @param annotationVisitor
	 *          an annotation visitor. Maybe {@literal null}.
	 */
	public void accept(final AnnotationVisitor annotationVisitor) {
		if (annotationVisitor != null) {
			if (values != null) {
				for (int i = 0, n = values.size(); i < n; i += 2) {
					String name = (String) values.get(i);
					Object value = values.get(i + 1);
					accept(annotationVisitor, name, value);
				}
			}
			annotationVisitor.visitEnd();
		}
	}

	/**
	 * Makes the given visitor visit a given annotation value.
	 *
	 * @param annotationVisitor
	 *          an annotation visitor. Maybe {@literal null}.
	 * @param name
	 *          the value name.
	 * @param value
	 *          the actual value.
	 */
	static void accept(final AnnotationVisitor annotationVisitor, final String name, final Object value) {
		if (annotationVisitor != null) {
			if (value instanceof String[]) {
				String[] typeValue = (String[]) value;
				annotationVisitor.visitEnum(name, typeValue[0], typeValue[1]);
			} else if (value instanceof AnnotationNode) {
				AnnotationNode annotationValue = (AnnotationNode) value;
				annotationValue.accept(annotationVisitor.visitAnnotation(name, annotationValue.desc));
			} else if (value instanceof List) {
				AnnotationVisitor arrayAnnotationVisitor = annotationVisitor.visitArray(name);
				if (arrayAnnotationVisitor != null) {
					List<?> arrayValue = (List<?>) value;
					for (int i = 0, n = arrayValue.size(); i < n; ++i) {
						accept(arrayAnnotationVisitor, null, arrayValue.get(i));
					}
					arrayAnnotationVisitor.visitEnd();
				}
			} else {
				annotationVisitor.visit(name, value);
			}
		}
	}
}
